Method and mechanical arrangement for producing a wall profile on a plastically deformable hollow body wall

Abstract

In order to produce a wall profile on an inside of a plastically deformable hollow body wall of a hollow body, a forming mandrel is arranged in the interior of a cavity of the hollow body so that the forming mandrel extends at the level of a first longitudinal portion of the hollow body wall with a mandrel portion having an enlarged cross-section, which has a forming mandrel profile portion and a cross-sectional oversize compared to a mandrel portion having a reduced cross-section, which extends at the level of a second longitudinal portion of the hollow body wall and has a further forming mandrel profile portion. A forming die is moved with a forming movement relative to the hollow body wall and relative to the mandrel portion with an enlarged cross-section and relative to the mandrel portion with a reduced cross-section of the forming mandrel.

What is claimed is: 
     
         1 . A method for producing a wall profile on an inside of a plastically deformable hollow body wall of a hollow body, wherein the hollow body wall delimits a cavity of the hollow body, which cavity is open on at least one side thus forming a cavity opening, the method comprising the following steps:
 arranging a forming mandrel having a forming mandrel profile in the interior of the cavity of the hollow body in such a way that the forming mandrel extends with the forming mandrel profile along the hollow body wall,   arranging a forming die provided with a die opening on an outside of the hollow body, and   moving the forming die with a forming movement along the hollow body wall passing through the die opening relative to the hollow body wall and relative to the forming mandrel, so as to produce the wall profile on the inside of the hollow body wall by plasticizing the hollow body wall due to the forming movement of the forming die, wherein a forming mandrel profile is reproduced on the inside of the hollow body wall as the wall profile,   wherein   the forming mandrel is arranged in the interior of the cavity of the hollow body in such a way that the forming mandrel extends at the level of a first longitudinal portion (l 1 ) of the hollow body wall with a mandrel portion having an enlarged cross-section, which mandrel portion has a forming mandrel profile portion and a cross-sectional oversize compared to a mandrel portion having a reduced cross-section, which mandrel portion having a reduced cross section extends at the level of a second longitudinal portion (l 2 ) of the hollow body wall following the first longitudinal portion (l 1 ) of the hollow body wall along the hollow body wall and has a further forming mandrel profile portion and   wherein the forming die is moved during the forming movement relative to the hollow body wall and relative to the mandrel portion having an enlarged cross-section and relative to the mandrel portion having a reduced cross-section of the forming mandrel,   wherein, due to the forming movement of the forming die
 on an inside of the first longitudinal portion (l 1 ) of the hollow body wall, the forming mandrel profile portion of the mandrel portion having an enlarged cross-section is reproduced as a first wall profile portion of the wall profile, and 
 on an inside of the second longitudinal portion (l 2 ) of the hollow body wall, the forming mandrel profile portion of the mandrel portion having a reduced cross-section is reproduced as a second wall profile portion of the wall profile. 
   
     
     
         2 . The method according to  claim 1 , wherein the forming mandrel is arranged in the interior of the cavity of the hollow body in such a way that the forming mandrel extends with the mandrel portion having an enlarged cross-section at the level of a first longitudinal portion (l 1 ), provided with the cavity opening, of the hollow body wall. 
     
     
         3 . The method according to  claim 1 , wherein the forming movement of the forming die is superimposed with a mandrel movement of the forming mandrel directed opposite to the forming movement of the forming die, wherein the forming mandrel is connected to the hollow body wall in a positive-fitting and/or force-fitting manner during the mandrel movement. 
     
     
         4 . The method according to  claim 1 , wherein a wall toothing is produced as a wall profile on the inside of the hollow body wall with teeth and intertooth spaces running along the hollow body wall,
 wherein the forming mandrel has, as a forming mandrel profile, a forming mandrel toothing with mandrel teeth and with mandrel intertooth spaces which open towards the inside of the hollow body wall,   wherein the mandrel portion having an enlarged cross-section has a forming mandrel toothing portion as the forming mandrel profile portion, and the mandrel portion having a reduced cross-section has a further forming mandrel toothing portion as the further forming mandrel profile portion and   wherein, due to the forming movement of the forming die
 on an inside of the first longitudinal portion (l 1 ) of the hollow body wall, the forming mandrel toothing portion of the mandrel portion having an enlarged cross-section is reproduced as a first wall toothing portion of the wall toothing, and 
 on an inside of the second longitudinal portion (l 2 ) of the hollow body wall, the forming mandrel toothing portion of the mandrel portion having a reduced cross-section is reproduced as a second wall toothing portion of the wall toothing. 
   
     
     
         5 . The method according to  claim 4 , wherein
 the forming die is provided at the die opening with a forming die toothing with die teeth and with die intertooth spaces which open towards the outside of the hollow body wall passing through the die opening and   wherein, during the forming movement of the forming die, die teeth arranged on the outside of the hollow body wall and mandrel intertooth spaces arranged on the inside of the hollow body wall, as well as die intertooth spaces arranged on the outside of the hollow body wall and mandrel teeth arranged on the inside of the hollow body wall, are situated opposite one another on the hollow body wall, wherein the die teeth act upon plasticized material of the hollow body wall in a direction of the mandrel intertooth spaces situated opposite the die teeth, thus forming the wall toothing on the inside of the hollow body wall and a wall toothing on the outside of the hollow body wall.   
     
     
         6 . The method according to  claim 1 , wherein the hollow body is a tubular hollow body having a plastically deformable tube wall, and wherein the wall profile is produced on the inside of the plastically deformable tube wall of the tubular hollow body, wherein the tube wall delimits the cavity of the tubular hollow body, which cavity is open on at least one side thus forming the cavity opening. 
     
     
         7 . The method according to  claim 1 , wherein, before the forming of the hollow body wall, a thickness of the hollow body wall in the first longitudinal portion (l 1 ) of the hollow body wall is reduced compared to a thickness of the hollow body wall in the second longitudinal portion (l 2 ) of the hollow body wall. 
     
     
         8 . A mechanical arrangement for producing a wall profile on an inside of a plastically deformable hollow body wall of a hollow body with a cavity, delimited by the hollow body wall, which is open on at least one side thus forming a cavity opening, wherein the mechanical arrangement comprises a forming device for forming the hollow body wall, the forming device comprising:
 a forming mandrel which has a forming mandrel profile and which is configured to be arranged in an interior of the cavity of the hollow body such that the forming mandrel extends with the forming mandrel profile along the hollow body wall,   a forming die which is provided with a die opening and which is configured to be arranged on an outside of the hollow body and   a forming drive, by which the forming die arranged on the outside of the hollow body wall can be moved with a forming movement along the hollow body wall passing through the die opening relative to the hollow body wall and relative to the forming mandrel, wherein the forming die is configured to produce the wall profile on the inside of the hollow body wall by plasticizing material of the hollow body wall due to the forming movement of the forming die, and the forming mandrel profile is reproduced on the inside of the hollow body wall as the wall profile,   wherein the forming mandrel has a mandrel portion with an enlarged cross-section and a mandrel portion with a reduced cross-section, wherein the mandrel portion having an enlarged cross-section and the mandrel portion having a reduced cross-section each have a forming mandrel profile portion and wherein the mandrel portion having an enlarged cross-section has a cross-section oversize compared to the mandrel portion having a reduced cross-section,   wherein the forming mandrel is configured to be arranged in the interior of the cavity of the hollow body in such a way that the forming mandrel extends, with the mandrel portion having an enlarged cross-section, at a level of a first longitudinal portion (l 1 ) of the hollow body wall and, with the mandrel portion having a reduced cross-section, at a level of a second longitudinal portion (l 2 ) of the hollow body wall following the first longitudinal portion (l 1 ) of the hollow body wall along the hollow body wall, and   wherein the forming die is movable by the forming drive during the forming movement along the hollow body wall relative to the mandrel portion having an enlarged cross-section and relative to the mandrel portion having a reduced cross-section of the forming mandrel, such that, due to the forming movement of the forming die,
 on the inside of the first longitudinal portion (l 1 ) of the hollow body wall, the forming mandrel profile portion of the enlarged mandrel portion having an enlarged cross-section is reproduced as a first wall profile portion of the wall profile, and 
 on the inside of the second longitudinal portion (l 2 ) of the hollow body wall, the forming mandrel profile portion of the mandrel portion having a reduced cross-section is reproduced as a second wall profile portion of the wall profile. 
   
     
     
         9 . The mechanical arrangement according to  claim 8 , wherein a mandrel drive is provided and is configured for moving the forming mandrel with a mandrel movement superimposed on the forming movement of the forming die and directed counter to the forming movement of the forming die, wherein the forming mandrel is connected to the hollow body wall in a positively-fitting and/or force-fitting manner during the mandrel movement. 
     
     
         10 . The mechanical arrangement according to  claim 8 , further comprising a device for partially reducing the thickness of the hollow body wall, the device being configured to reduce, prior to the forming of the hollow body wall, the thickness of the hollow body wall in the first longitudinal portion (l 1 ) of the hollow body wall compared to the thickness of the hollow body wall in the second longitudinal portion (l 2 ) of the hollow body wall. 
     
     
         11 . The mechanical arrangement according to  claim 10 , wherein the device for partially reducing the thickness of the hollow body wall is a rotary swaging device.